The subject of the invention is a milling cutter and a cutter holder particularly, although not exclusively, for surgical use.
The object of the invention is to produce a quick fixing for a milling cutter, particularly for an essentially flat, disk-shaped cutter.
The milling cutter and the cutter holder, according to the invention, are ones wherein the cutter has a part of flat annular shape pierced with at least two fixing holes uniformly distributed on a circle and with at least one locking hole, and the cutter holder has, on the one hand, at least two parallel fixed fingers uniformly distributed on a circle of the same diameter as the circle passing through the fixing holes in the cutter, these fingers having a head of a diameter smaller than the diameter of the fixing holes, a groove under this head, of a height corresponding to the thickness of the annular part of the cutter, and, under the groove, a diameter larger than the diameter of the fixing holes and, on the other hand, at least one locking finger parallel to the fixed fingers and moveable parallel to the fixed fingers, this moving finger occupying, around the axis of the support, relative to the fixed fingers, the same position as the locking hole relative to the fixing holes but with an angular offset in a direction which is the opposite to the direction of rotation of the cutter, so that once the cutter has been engaged over the fixed fingers and engaged in the grooves, in the opposite direction to its direction of rotation, introducing the moving finger into the locking hole has the effect of locking the cutter in the grooves.
The locking finger may simply be cylindrical. In this case, to avoid the fixing exhibiting angular backlash, the fixing hole and the locking finger need to be made and positioned with great accuracy. This requirement can be dispensed with by using a locking finger the end of which is conical so that engagement of the conical end in this locking hole has the effect of pushing the cutter into the grooves.
The cutter preferably has three locking holes to which three conical-ended locking fingers on the cutter holder correspond.
This fixing mode can apply to any cutter which has a flat annular part, the central part possibly having the desired shape, for example hemispherical or conical.
According to one preferred embodiment of the invention, the fixed fingers are carried by a flange, while the locking fingers arc carried by an annular support constrained so as to slide axially on the cutter holder, passing through the flange and guided in this flange.
The annular support of the locking fingers is pushed by a spring so that when the annular support is released, the conical fingers automatically engage in the locking holes. The spring maintains the lateral thrust of the locking fingers on the cutter.
This milling cutter and cutter holder assembly is particularly intended for one-use surgical cutters.